PESTS OF WHEAT :: Major Pests :: Ghujhia Weevil

3. Ghujhia Weevil: Tanymecus indicus (Curculionidae: Coleoptera)

Distribution and status: Sporadic pest of considerable importance in wheat growing areas.

Host range: Germinating Rabi crops viz.,Wheat, barley, gram and mustard

Damage symptoms: Only adults feed on leaves and tender shoots of the host plants. They cut the germinating seedlings at the ground level. Often the crop is resown. The damage is particularly serious during October-November when the rabi crops are germinating.

Bionomics: Weevils are earthen grey and measure about 6.8 mm in length and 2.4 mm in width. Their fore wings are oblong and hind wings are more or less triangular, but they cannot fly. The pest is active from June to December and undergoes larval or pupal diapause during rest of the year in the soil. Weevils emerging in June mature sexually in October. They mate frequently and lay 6-76 eggs in 5-11 installments in the soil under clods or in crevices in the ground. The egg period is 6-7 weeks. Young grubs enter the soil. Grub period is 10-18 days and pupate in earthen chambers at a depth of 15-60 cm. The pupal stage lasts 7-9 weeks, and the adults emerge next year in June or July. The pest has only one generation in a year.

Management: Dust carbaryl or malathion 5 D @ 25 kg per ha.